Parrots' behaviors mirror human mental disorders

WEST LAFAYETTE, Ind. - The bird doing loop-the-loops in the cage and pulling out its feathers is not just playing and preening. Stress may cause these activities and also may provide insight into similar human behaviors, according to researchers.

A study of abnormal repetitive behaviors practiced by Orange-winged Amazon parrots indicates that environment plays a role in two types of behavior that the caged birds perform. One of the behaviors, feather picking, closely mirrors compulsive behaviors in humans, according to Purdue University and University of California at Davis researchers. The study also helped debunk a time-worn belief that parrots teach each other feather picking.

"There is a lot of merit in studying abnormal behaviors just in terms of figuring out ways to control them for the welfare of both companion animals and those bred for production agriculture," said Joseph Garner, a Purdue assistant professor of animal sciences and the study's lead author. "Another benefit is that if animal abnormal behavior is caused in the same way as in humans, then we may have a whole new range of model animals for studying human mental disorders."

Results of the research are scheduled for publication in the January issue of Applied Animal Behaviour Science and currently are published on the journal's Web site.

The researchers initially were trying to determine if parrots' abnormal behaviors are of two categories. One category is composed of a constant repetition of meaningless gestures or movements called stereotypies, and the other is a repetition of inappropriate complex behavior that normally would have a specific goal, such as feather picking.

"I've thought for awhile that we should start looking at these behaviors in animals as if they are two different types," Garner said. "Then, if we treated stereotypies and compulsive behaviors as if they were in humans, maybe we would improve our treatments in birds."

Behavior problems, including feather picking and screeching, can be very distressing to owners and contribute to birds being surrendered for adoption, Garner said. Many of these birds are euthanized because their behavior is untreatable. People often mistake the stereotypies, such as walking circles on the sides of cages or twirling pieces of feed in their beaks, as playing.

All of these behaviors are abnormal and often are a reaction to environmental factors, the researchers said. The major factor triggering an increase in stereotypies in parrots was a lack of neighbors for socialization, according to the study.

In contrast, physical environment, including cage placement, was a key factor generating feather picking by the parrots used in the study, Garner said. The scientists found that parrots with cages that didn't allow a view of doors where people entered the room were less likely to engage in feather picking.

"For parrot owners and breeders, one thing our research shows is that it might be worth putting a lot of thought into where the cage is positioned in the room," Garner said. "I think with a lot of care and a lot of forethought, these behaviors are manageable and preventable, especially considering our earlier work that demonstrated the positive effects of social housing and environmental enrichments, such as foraging and climbing devices.

"We're just translating what the animals are trying to tell people through behavior. We hope the breeders can turn it into something practical."

Sixty-four birds were used in the study, evenly divided between males and females. They ranged in age from 5-11 years old. Lights were on in the rooms from 8 a.m. until 7 p.m. each day, and the birds were videotaped from 9-11 a.m. Each bird was given a score depending on how much it picked at its feathers.

The results showed that birds with no view of the entry door showed no difference in feather picking no matter how close they were to the door, the researchers reported. In contrast, birds that faced the door feather picked more depending on the distance of their cage to the door.

The researchers also found that feather picking was more common in female birds, which parallels compulsive hair pulling in people, called trichotillomania. According to the study results, age didn't impact the amount of feather picking.

"Behavior is like an organ as much as a lung or a heart is," Garner said. "Like an organ, behavior highly affects us, and it's the animal's first and last resort for defense. Animals change their behavior in order to meet challenges in the environment."

Abnormal behaviors can have a major impact not only on private owners, but also on entire industries.

A study conducted in Australia a few years ago showed that feather picking by hens caused them to eat more to make up for loss of body heat. This resulted in an 8 percent loss in income, or as much as a $50 million loss for the Australian egg-laying industry.

People often think animals teach each other certain bad behaviors, Garner said. But he and his research team took into consideration a number of factors, such as age, genetic relationship, placement of cages and sex, and it became clear that the parrots were reacting to their environment and/or to a genetic malfunction.

"We busted the myth that feather picking is socially transmitted, at least in the birds we studied," he said. "This is exciting because with the strong heritability of feather picking that we found, it might be possible to breed parrots that don't have the propensity to develop this behavior."

The other researchers involved in this study were Cheryl Meehan, Thomas Famula and Joy Mench all of the UC Davis Department of Animal Sciences.

The Kenneth A. Scott Charitable Trust, a Key Bank Trust, provided support for the project.

Note to Journalists: A copy of the study is available by contacting Susan A. Steeves at ssteeves@purdue.edu, (765) 496-7481

PHOTO CAPTION:
Some animal behaviors closely mirror human mental disorders, so Joseph Garner, a Purdue assistant professor of animal sciences, and his colleagues at University of California at Davis, study parrots in hopes of improving the understanding of such problems as compulsive behavior. (Purdue Agricultural Communication photo/Tom Campbell)

PHOTO CAPTION:
Orange-winged Amazon parrots often exhibit inappropriate behavior, some of which is very similar to compulsive behaviors in people. This parrot has lost many of its feathers by constantly picking at them. (Photo courtesy of Cheryl Meehan, University of California at Davis)

Stereotypies and psychogenic feather picking represent two distinct forms of abnormal behavior in parrots, with implications for welfare and owner relinquishment. While both behaviors are common in captive parrots, relatively little is known about the factors that may predispose a parrot to their development. To assess the effects of potential social, environmental, and genetic factors, we performed an epidemiological study of a colony of 64 Orange-winged Amazon parrots. We first used mixed model methods to assess the narrow heritability, or genetic determination, of stereotypy, which was -0.08 +/- 0.14, and feather picking, which was 1.14 +/- 0.27. We then focused our study on one room of 27 birds that had always been housed in the same cage location. We examined the effects of neighbor behavior, number of neighbors, sex, family, age, cage row (beside an aisle or beside a wall), and distance from the door, on each behavior. Stereotypy was negatively correlated with the number of neighbors, but was unaffected by any other factor. In contrast, feather picking was affected by family, was more severe in females, and was progressively more severe in birds housed closer to the door when they had a direct line of sight of the door. Feather picking was spatially clustered in the room, but siblings from particular families were also more likely to be housed as neighbors than were non-siblings. Given the strong effect of family on feather picking and the effect of proximity to the door, these factors together explained the spatial clustering of feather picking. In addition, the feather picking of neighbors was uncorrelated. Thus, there was no evidence for social transmission of feather picking. Our results indicate that cages should be located away from potential stressors, and suggest that there is a potential for breeding against feather picking behavior in parrots. Finally, the markedly different genetic and environmental effects on stereotypies versus feather picking emphasizes that these are two distinct classes of abnormal repetitive behavior in parrots.